virus

 
Pronunciation: /ˈvʌɪrəs/

noun

  • 1an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host: the hepatitis B virus [as modifier]: a virus infection
  • an infection or disease caused by a virus: I’ve had a virus
  • a harmful or corrupting influence: the virus of cruelty that is latent in all human beings
  • 2 (also computer virus) a piece of code which is capable of copying itself and typically has a detrimental effect, such as corrupting the system or destroying data.

Origin:

late Middle English (denoting the venom of a snake): from Latin, literally 'slimy liquid, poison'. The earlier medical sense, superseded by the current use as a result of improved scientific understanding, was 'a substance produced in the body as the result of disease, especially one capable of infecting others'

Spelling rule

Add -es to make the plural of words ending in -s: viruses.